I would love for Rudy to run as federalist. The only way he can defuse the abortion issue — in the primaries at least — is to say Roe v. Wade is crappy law (which it is) and that while he’s personally pro-choice, it’s up to the states and the individual to figure this stuff out. The problem is that running against Roe in the general election isn’t a winner.
More broadly, I don’t think Giuliani is plausible as a states’ rights-laboratories of democracy kind of guy. He was federal prosecutor and has a G-man sensibility. And as a New York City Mayor he’s accustomed to begging from both state and federal agencies. He likes to run things. He’s going to run as the can-do Republican (as is Romney and, if he runs, Gingrich). And running as the can-do guy runs against the grain of running as a won’t-do-guy (The Coolidge Doctrine, in other words).